Power cut detection

GivEnergy Products GivEnergy All In One
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We are considering having an All-In-One installed. Our rural mains supply is not very reliable so the gateway would be very useful.

I will have to inhibit our heat pump to stop it depleting the AIO battery too much during longer power cuts. That should be easy as the heat pump accepts volt-free contacts (from an external relay) to prevent the compressor from running.

Does the Givenergy gateway have an output to indicate when mains is on and off ?

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You could very easily add one. It doesnt have dry contacts. But you could add a small relay on the Grid side, to control the HP.

Or as Ive done, integrate it all into HomeAssistant and write any logic you wish

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Thanks, that will work if you are saying the gateway has space for a 6A mcb to feed a relay from the grid supply (can’r risk wiring a 230V relay directly to the grid supply as any fault current would only be limited by the 80A incoming fuses – eek ! :slightly_smiling_face:)

I have played with a few sensors on home assistant in the past but I am not a confident enough user to trust it with something as critical as the heat pump shutdown.

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One solution very easy to do. Wire the HP direct into the GW, like an EV charger would be.
In the GW are 3 spare ways, in here you could add a 2 pole RCBO. Input from the grid busbar (Before the GW contactors, but after the grid metering)
This position on grid the HP would be met by battery in normal balance load mode.
If there was a power cut, the HP would have no supply and only the home on the load breaker would continue to be powered.

You would set teh gateway to calculated mode, vs measured, as the HP load would not be seen by the CT measuring the loads.
But as its after the grid CT, it would be included in balancing power from the battery.

Have your installer contact us, ask for Paul and we can draw a diagram to be clear how to achieve what you want.

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I would consider Paul’s ideas first (as he is the expert)

A second option if your not that much in a hurry, wait until the new GE AIO comes out?

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Thanks for that suggestion Paul. It would certainly conserve battery power, although a little drastic to turn off all heating the instant that mains power is lost.

I will just have to explain to my wife that even with a home battery we will still be huddled round a candle flame for a bit of warmth during power cuts. Only kidding, we can keep one room warm in longer outages by burning wood.

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Thanks for that info !

Found this video on YouTube where a nice man called Paul is describing an easy, configurable way to control a heat pump during a power cut
Gateway2

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The latest gateway (IIRC) has the ability to have critical and non critical loads split.

Also in Home Assistant, you can just look at the grid voltage reported (through the GIVTCP integration) on the gateway to detect if the grid has disconnected.

Here is some YAML that I use (I actually look for the grid frequency on the battery):

alias: Grid Power Lost
description: When the grid frequency drops under 1, it messages me
triggers:
  - trigger: numeric_state
    entity_id:
      - sensor.givtcpaio2_chxxxxxx_grid_frequency
    below: 1
conditions: []
actions:
  - data:
      title: xxxxxxxc
      data:
        push:
          sound:
            name: default
            critical: 1
            volume: 1
      message: "ALERT: Grid Power Lost"
    action: notify.main_notification_group
mode: single
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Not sure how much the AIOs are now but you could fit more than one if you need to run a heat pump at times.

Probably cheaper to fit 2-3-4 etc in one visit than fit 1 now & add 1 or more others later?

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The ability to have local monitoring/control of the battery is one of the things that attracted me to Givenergy products. Very reassuring to see sample lines of code for grid loss :+1:

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I am hoping we will be ok with a single battery. Having said that, I hadn’t given much thought to battery degradation over time.

Am I right in thinking that -

a) The mk 1 AIO needs a new G99 application for a later increase in battery capacity (because it means adding another inverter to the grid)

b) The mk2 AIO would not require any DNO approval for adding an extra battery, as it uses a single inverter ?

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You’d have to ask Giv, I don’t know which version I have, just that it’s got its own inverter but I suspect your DNO would want a new G98/99 anyway as your export capacity would potentially Increase.

It’s not so much the inverter as the potential export capacity & its effect on the grids phase balance in your area.

I don’t think battery degradation is much of an issue tbh. Most home batteries just won’t get the heavy drain & charge cycles the way EV batteries do.

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You can limit the export on the gateway, so if your G99 says 6kw, then you can set that as the battery export limit. But, if you add solar, at it is (say) 8kw, and your battery is full and your load is (say) 500w, then the rest will go to the grid, blowing the G99 ‘agreement’. You could add a solar diverter to fix.

TBH, I would not import at low rates (night) and then export from the battery to make money. Just move everything to electricity and run 24x7 on 7p electricity.